-LRB- CNN -RRB- -- Oscar Pistorius was not mentally incapacitated when he shot his girlfriend to death , a psychiatric assessment of the athlete has found .

The results of the assessment were revealed in court Monday when the Olympic sprinter 's trial resumed after a monthlong break for the evaluation .

According to the findings by an independent panel of doctors , Pistorius did not suffer from a mental defect or mental illness at the `` time of the commission of the offense that would have rendered him criminally not responsible of the offenses charged . ''

The report added that `` Mr. Pistorius was capable of appreciating the wrongfulness of his act . ''

Had the doctors deemed Pistorius mentally incapacitated during the shooting , the trial would have immediately ended in a verdict of not guilty by reason of mental illness .

Pistorius , 27 , is accused of murdering his girlfriend , 29-year-old model and law school graduate Reeva Steenkamp , in his home in February 2013 .

Pistorius admits shooting Steenkamp through a closed door , killing her , but has told the court in Pretoria , South Africa , that he mistook her for an intruder . He has pleaded not guilty .

The state says Pistorius argued with Steenkamp before killing her .

On May 20 , trial Judge Thokozile Masipa ordered Pistorius to report for a psychiatric evaluation to establish whether he was criminally responsible for his actions .

The prosecution and defense said they accepted the report 's findings . The defense has resumed its case .

Psychiatrist 's testimony

Pistorius ' psychiatric testing last month was triggered by the testimony of a psychiatrist who said the sprinter has suffered from generalized anxiety disorder since he was an infant , stemming partly from the amputation his lower legs .

The disorder meant Pistorius had `` excessive '' concerns about security and felt threatened even when , objectively , he was not , Dr. Merryll Vorster testified on May 12 .

After Vorster 's testimony , prosecutor Gerrie Nel filed a motion asking the judge to require psychiatric tests , arguing that if there was any chance the defendant 's mental health was an issue , the court must `` err on the side of caution . ''

Nel 's extremely unusual move was essentially an effort to maneuver the court into considering an insanity or `` capacity '' defense even though the athlete 's legal team is not mounting one , CNN legal analyst Kelly Phelps said .

Phelps said Nel appeared to be placing a high-stakes bet that experts would disagree with Vorster 's evidence .

Pistorius ' lead defense lawyer , Barry Roux , argued against the tests , describing Nel 's reading of the law as `` unfortunate . ''

But Masipa ordered the evaluation , saying the defense 's act of putting a psychiatrist on the stand had raised the question of the athlete 's mental health . Testing began on May 26 .

Light and balance

When court resumed Monday , the defense called Pistorius ' orthopedic surgeon Dr. Gerald Versfeld as a witness .

Versfeld described the limitations of Pistorius ' mobility , based on his examination of the athlete and Pistorius ' own description .

In his cross-examination , Nel focused on the effect of light on Pistorius ' balance .

In his affidavit , Pistorius said he had rushed to the bathroom on stumps with a pistol after hearing a noise . He said he had been too scared to turn the lights on . `` It was pitch dark in the bedroom , and I thought Reeva was in bed . ''

Nel suggested to Versfeld that it would have been `` highly unlikely '' that Pistorius would have been able to walk on his stumps without falling if it had been pitch black in the bedroom , given the objects in it .

`` If it was indeed pitch dark , that is so , '' Versfeld replied .

Roux referred to Pistorius ' evidence that there had been slight illumination .

`` The moment there is light available , he will be able to use his vision to balance , '' Versfeld said , agreeing that if Pistorius had known the objects in his room , that would also have helped protect him from falling .

Sound of screams

Acoustic engineer Ivan Lin was the second witness to take the stand Monday .

He told court that `` typically , '' one can differentiate between male and female screams , but not without exception .

Previous witnesses have described hearing a woman 's screams between shots the night Steenkamp died , but the defense has argued that Pistorius sounds `` like a woman screaming '' when he 's anxious .

Lin said it would be `` impossible '' to replicate the `` highly complex sound transmission '' from Pistorius ' house the night he killed Steenkamp . He explained how different variables could affect the transmission .

Verdict

At the trial 's conclusion , Masipa will have to decide whether Pistorius genuinely made a mistake or killed Steenkamp intentionally .

If she does not believe the athlete thought there was an intruder , she will find him guilty of murder and sentence him to at least 15 years in prison and possibly life . South Africa does not have the death penalty .

If Masipa accepts that Pistorius did not know Steenkamp was the person he was shooting at , she could find him guilty of culpable homicide , a lesser charge than murder , or acquit him , according to CNN legal analyst Kelly Phelps .

A verdict of culpable homicide would leave the sentence at Masipa 's discretion .

Read more : Judge sends Pistorius for psychiatric tests

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A panel of doctors finds Olympian Oscar Pistorius mentally fit to stand trial

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Pistorius is accused of deliberately shooting his girlfriend Reeva Steenkamp

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He says he shot Steenkamp accidentally in his bathroom , mistaking her for an intruder

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The trial was halted in May after the judge ordered Pistorius to undergo psychiatric tests